/*
             MyUSB Library
     Copyright (C) Dean Camera, 2008.
              
  dean [at] fourwalledcubicle [dot] com
      www.fourwalledcubicle.com

 Released under the LGPL Licence, Version 3
*/

/** \file
 *
 *  USB Human Interface Device (HID) Class report descriptor processing routines. This file allows for the easy
 *  parsing of the complex HID report descriptor, which describes the data that the device transmits to the host.
 *
 *  The processed report is presented back to the user application as a flat structure containing each report
 *  item's IN, OUT and FEATURE (if desired) items along with each item's attributes.
 *
 *  This library portion also allows for easy setting and retrieval of data from a HID report. It currently
 *  supports devices with one one single HID report containing multiple items (i.e. no multiple report devices).
 *
 *  By default, FEATURE reports and IN/OUT reports with constant data are ignored in the HID report when processed
 *  to save on memory. This can be overridden by defining the HID_ENABLE_FEATURE_PROCESSING or
 *  HID_INCLUDE_CONSTANT_DATA_ITEMS tokens in the user project makefile, passing them to the compiler via the -D
 *  switch.
 */

#ifndef __HIDPARSER_H__
#define __HIDPARSER_H__

	/* Includes: */
		#include <string.h>

		#include "HIDReportData.h"

		#include "../../../Common/Common.h"

	/* Enable C linkage for C++ Compilers: */
		#if defined(__cplusplus)
			extern "C" {
		#endif

	/* Preprocessor checks and defines: */
		#if !defined(HID_STATETABLE_STACK_DEPTH) || defined(__DOXYGEN__)
			/** Constant indicating the maximum stack depth of the state table. A larger state table
			 *  allows for more PUSH/POP report items to be nested, but consumes more memory. By default
			 *  this is set to 3 levels (allowing for two PUSHes to be nested) but this can be overridden by
			 *  defining HID_STATETABLE_STACK_DEPTH to another value in the user project makefile, passing the
			 *  define to the compiler using the -D compiler switch.
			 */
			#define HID_STATETABLE_STACK_DEPTH    3
		#endif
		
		#if !defined(HID_USAGE_STACK_DEPTH) || defined(__DOXYGEN__)
			/** Constant indicating the maximum stack depth of the usage table. A larger usage table
			 *  allows for more USAGE items to be indicated sequentially for REPORT COUNT entries of more than
			 *  one, but requires more stack space. By default this is set to 8 levels (allowing for a report
			 *  item with a count of 8) but this can be overridden by defining HID_USAGE_STACK_DEPTH to another
			 *  value in the user project makefile, passing the define to the compiler using the -D compiler
			 *  switch.
			 */
			#define HID_USAGE_STACK_DEPTH         8
		#endif

		#if !defined(HID_MAX_COLLECTIONS) || defined(__DOXYGEN__)
			/** Constant indicating the maximum number of COLLECTION items (nested or unnested) that can be
			 *  processed in the report item descriptor. A large value allows for more COLLECTION items to be
			 *  processed, but consumes more memory. By default this is set to 5 collections, but this can be
			 *  overridden by defining HID_MAX_COLLECTIONS to another value in the user project makefile, passing
			 *  the define to the compiler using the -D compiler switch.
			 */
			#define HID_MAX_COLLECTIONS           5
		#endif
		
		#if !defined(HID_MAX_REPORTITEMS) || defined(__DOXYGEN__)
			/** Constant indicating the maximum number of report items (IN, OUT or FEATURE if enabled) that can be
			 *  processed in the report item descriptor. A large value allows for more report items to be
			 *  processed, but consumes more memory. By default this is set to 30 items, but this can be
			 *  overridden by defining HID_MAX_REPORTITEMS to another value in the user project makefile, passing
			 *  the define to the compiler using the -D compiler switch.
			 */
			#define HID_MAX_REPORTITEMS           30
		#endif

	/* Public Interface - May be used in end-application: */
		/* Enums: */
			/** Enum for indicating what type of report item an entry in a HID_ReportInfo_t ReportItem array is */
			enum HID_Types_t
			{
				REPORT_ITEM_TYPE_In                   = 0, /**< Indicates that the item is an IN report type. */
				REPORT_ITEM_TYPE_Out                  = 1, /**< Indicates that the item is an OUT report type. */
				REPORT_ITEM_TYPE_Feature              = 2, /**< Indicates that the item is a FEATURE report type. */
			};
			
			/** Enum for the possible error codes in the return value of the ProcessHIDReport() function */
			enum HID_Parse_ErrorCodes_t
			{
				HID_PARSE_Sucessful                   = 0, /**< Sucessful parse of the HID report descriptor, no error. */
				HID_PARSE_HIDStackOverflow            = 1, /**< More than HID_STATETABLE_STACK_DEPTH nested PUSHes in the report. */ 
				HID_PARSE_HIDStackUnderflow           = 2, /**< A POP was found when the state table stack was empty. */
				HID_PARSE_InsufficientReportItems     = 3, /**< More than HID_MAX_REPORTITEMS report items in the report. */
				HID_PARSE_UnexpectedEndCollection     = 4, /**< END COLLECTION found without matching COLLECTION item. */
				HID_PARSE_InsufficientCollectionPaths = 5, /**< More than HID_MAX_COLLECTIONS collections in the report. */
				HID_PARSE_UsageStackOverflow          = 6, /**< More than HID_USAGE_STACK_DEPTH usages listed in a row. */
			};
		
		/* Type Defines: */
			/** Type define for a COLLECTION object. Contains the collection attributes and a reference to the
			 *  parent collection if any.
			 */
			typedef struct CollectionPath
			{
				uint8_t                      Type;   /**< Collection type (for example "Generic Desktop"). */
				uint16_t                     Usage;  /**< Collection usage. */
				struct CollectionPath*       Parent; /** Reference to parent collection, or NULL if root collection. */
			} CollectionPath_t;
		
			/** Type define for an attribute with both minimum and maximum values (e.g. Logical Min/Max). */
			typedef struct
			{
				uint32_t                     Minimum; /**< Minimum value for the attribute. */
				uint32_t                     Maximum; /**< Maximum value for the attribute. */
			} HID_MinMax_t;

			/** Type define for the Unit attributes of a report item. */
			typedef struct
			{
				uint32_t                     Type;     /**< Unit type (refer to HID specifications for details). */
				uint8_t                      Exponent; /**< Unit exponent (refer to HID specifications for details). */
			} HID_Unit_t;
			
			/** Type define for the Usage attributes of a report item. */
			typedef struct
			{
				uint16_t                     Page;   /**< Usage page of the report item. */
				uint16_t                     Usage;  /**< Usage of the report item. */
				HID_MinMax_t                 MinMax; /**< Usage minimum and maximum of the report item. */
			} HID_Usage_t;

			/** Type define for all the data attributes of a report item, except flags. */
			typedef struct
			{
				uint8_t                      BitSize;  /**< Size in bits of the report item's data. */
				
				HID_Usage_t                  Usage;    /**< Usage of the report item. */
				HID_Unit_t                   Unit;     /**< Unit type and exponent of the report item. */
				HID_MinMax_t                 Logical;  /**< Logical minimum and maximum of the report item. */
				HID_MinMax_t                 Physical; /**< Physical minimum and maximum of the report item. */
			} HID_ReportItem_Attributes_t;
			
			/** Type define for a report item (IN, OUT or FEATURE) attributes and other details. */
			typedef struct
			{
				uint16_t                     BitOffset;      /**< Bit offset in the IN, OUT or FEATURE report of the item. */
				uint8_t                      ItemType;       /**< Report item type, a value in HID_Types_t. */
				uint16_t                     ItemFlags;      /**< Item data flags, such as constant/variable, etc. */
				CollectionPath_t*            CollectionPath; /**< Collection path of the item. */

				HID_ReportItem_Attributes_t  Attributes;     /**< Report item attributes. */
							
				uint32_t                     Value;          /**< Current value of the report item. */
			} HID_ReportItem_t;

			/** Type define for a complete processed HID report, including all report item data and collections. */
			typedef struct
			{
				uint8_t                      TotalReportItems; /**< Total number of report items stored in the
				                                                *   ReportItems array. */
				HID_ReportItem_t             ReportItems[HID_MAX_REPORTITEMS]; /**< Report items array, including
			                                                                    *   all IN, OUT and FEATURE items. */

				CollectionPath_t             CollectionPaths[HID_MAX_COLLECTIONS]; /**< All collection items, referenced
				                                                                    *   by the report items. */
			} HID_ReportInfo_t;
			
		/* Function Prototypes: */
			/** Function to process a given HID report returned from an attached device, and store it into a given
			 *  HID_ReportInfo_t structure.
			 *
			 *  \param ReportData  Buffer containing the device's HID report table
			 *  \param ReportSize  Size in bytes of the HID report table
			 *  \param ParserData  Pointer to a HID_ReportInfo_t instance for the parser output
			 *
			 *  \return A value in the HID_Parse_ErrorCodes_t enum
			 */
			uint8_t ProcessHIDReport(const uint8_t* ReportData, uint16_t ReportSize, HID_ReportInfo_t* const ParserData)
									  ATTR_NON_NULL_PTR_ARG(1, 3);

			/** Extracts the given report item's value out of the given HID report and places it into the Value
			 *  member of the report item's HID_ReportItem_t structure.
			 *
			 *  \param ReportData  Buffer containing an IN or FEATURE report from an attached device
			 *  \param ReportItem  Pointer to the report item of interest in a HID_ReportInfo_t ReportItem array
			 */
			void    GetReportItemInfo(const uint8_t* ReportData, HID_ReportItem_t* const ReportItem)
									  ATTR_NON_NULL_PTR_ARG(1, 2);

			/** Retreives the given report item's value out of the Value member of the report item's
			 *  HID_ReportItem_t structure and places it into the correct position in the HID report
			 *  buffer. The report buffer is assumed to have the appropriate bits cleared before calling
			 *  this function (i.e., the buffer should be explicitly cleared before report values are added).
			 *
			 *  \param ReportData  Buffer holding the current OUT report data
			 *  \param ReportItem  Pointer to the report item of interest in a HID_ReportInfo_t ReportItem array
			 */
			void    SetReportItemInfo(uint8_t* const ReportData, const HID_ReportItem_t* ReportItem)
									  ATTR_NON_NULL_PTR_ARG(1, 2);

	/* Private Interface - For use in library only: */
	#if !defined(__DOXYGEN__)
		/* Type Defines: */
			typedef struct
			{
				 HID_ReportItem_Attributes_t Attributes;
				 uint8_t                     ReportCount;
			} HID_StateTable_t;
	#endif
			
	/* Disable C linkage for C++ Compilers: */
		#if defined(__cplusplus)
			}
		#endif

#endif
